I just downloaded
GAB
but I have no idea how to install it. All I got from the download is a file that I can't open...am I supposed to be able to open this file or upload it to my site directly? What program do I use to open it...is there a .zip file somewhere?

I'm a completely lost newbie

GAB

GAB is a highly configurable banner system that allows you to customize banners for vBulletin easily. Determine which usergroups see banners, which ones can disable them, which pages have banners and where. GAB is the one stop shop for banner advertising.